1. Technical Field
The present invention relates to a light emitting and receiving device.
2. Related Art
In a semiconductor light emitting device used in optical communication and other fields, in general, a half-silvered mirror or a diffraction element disposed external to the device extracts part of the light having exited out of the device, and the extracted light is detected by a light receiving element. The amount of light is thus adjusted or otherwise processed.
For example, JP-A-10-3691 proposes an optical pickup apparatus in which a spectroscopic prism or any other suitable component separates the light from a laser diode and a monitoring photodiode detects the separated light.
In the method disclosed in JP-A-10-3691, however, since the light emitting element and the light receiving element are separate components, the extra prism or any other suitable component is required, resulting in increase in the number of parts and difficulty in size reduction. Further, to use a display apparatus, it is necessary to detect the amounts of light from a plurality of laser diodes separately, but it is sometimes difficult to provide a light receiving element for each of the plurality of laser diodes.